The study of genetic material recovered directly from an environmental sample by sequencing the genetic material is referred to as metagenomics. Metagenomics provides information pertaining to taxonomic diversity and physiology of various organisms present in an environmental sample. In order to gather information pertaining to taxonomic classification and community structure of an environmental sample, the genetic material obtained directly from the environmental sample is sequenced into a plurality of sequences, called metagenomic sequences.
Taxonomic classification of these metagenomic sequences helps reconstructing the community structure of the environmental sample. Further, to understand microbial ecology of various environmental samples and identify the key organisms responsible for the specific phenotypic characteristic exhibited by an environmental sample, such as specific disease conditions or physiological disorders like obesity, the community structures within the various environmental samples may be compared. Various techniques have been implemented to perform a comparative analysis of the community structures. Generally such techniques seek to group or differentiate the environmental samples based only on the presence or absence of a specific organism(s) under certain environmental conditions. As a result, such techniques may provide an incomplete picture of structure and dynamics of microbial communities within the environmental samples under analysis.